Blender2.77 layout sharing
When you create a new layout in the Themes tab in the User preferences, then a xml file gets created in the Blender app data folder. At Windows 7 it's 

C:\Users\YOURUSERNAME\AppData\Roaming\Blender Foundation\Blender\2.77\scripts\presets\interface_theme

Let's say you added a new preset and named it mytheme, then you will find a mytheme.xml in the above folder.

You can grab this xml file, and other users can then install this xml file as a new theme with the Install Theme button in the Themes tab in the User Preferences.